1. Field of the Invention
The present invention relates to an integrated circuit (IC) transporting and handling or processing apparatus (commonly called an IC handler) used, for example, in an IC testing apparatus (commonly called an IC tester) for testing ICs.
2. Description of the Related Art
FIG. 1 shows a diagrammatical arrangement of a prior art IC handler referred to as a horizontal transporting system. A plurality of tray groups 2 are disposed along one side, namely, the lower side 1A in the drawing, of a frame 1 which serves as a base. Each tray in the tray groups 2 is loaded with ICs. Each of the tray groups 2A-2E consists of a stack of multiple trays loaded up in vertical direction. The leftmost tray group 2A in the drawing is positioned at a loader section. ICS undergoing a test (hereafter ICs to be tested) have been loaded on each tray in the tray group 2A at the loader section.
A carrier arm 3 picks up two ICs at a time, in this example, out of the uppermost tray of the tray group 2A which is a stack of trays and transports them onto a turntable 4 called "soak stage". On the turntable 4, in order to define the positions for receiving ICs, are formed positioning recessed portions 5 arranged along two concentric circular lines at intervals of a constant angle as shown in FIG. 2.
Each recessed portion 5 is of substantially square shape in plan and the four sides thereof are surrounded by upwardly inclined walls (surfaces). Every time the turntable 4 rotates by one pitch, two ICs are fallen into two respective recessed portions 5 one being arranged in the inner circular line and the other in the outer circular line.
A reference numeral 6 denotes a contact arm for transferring ICs conveyed by the turntable 4 to a testing section 7. The contact arm 6 is adapted to pick up two ICs at a time by suction out of the respective positioning recessed portions 5 on the turntable 4 and transports these ICs to the testing section 7. The contact arm 6 has three arms and performs the operation of sequentially transferring the ICs to the testing section 7 and the operation of sequentially transferring the tested ICs to a transfer arm 8 located at an exit side by rotation of the three arms.
Further, the IC handler is constructed such that the turntable 4, the contact arm 6, and the testing section 7 are placed in a constant temperature or thermostatic room (chamber) 9, and ICs to be tested are maintained at a predetermined temperature within this thermostatic chamber 9 and undergo a test therein.
ICs taken out from the thermostatic chamber 9 by the transfer arm 8 located at the exit side of the thermostatic chamber are sorted on the basis of the test results and stored in corresponding one of three tray groups 2C, 2D and 2E in this example located at an unloader section. For example, non-conforming or bad ICs (ICs having a defect or failure) are stored in a tray of the rightmost tray group 2E, conforming or good ICs (ICs having no defect or failure) are stored in a tray of the tray group 2D positioned at the left side of the tray group 2E, and ICs which are needed to undergo a retest are stored in a tray of the tray group 2C positioned at the left side of the tray group 2D. This sorting of ICs is performed by a carrier arm 11.
Further, the tray group 2B located at the second left side position is an empty tray group located at a buffer section for accommodating trays emptied of ICs in the loader section. When the uppermost tray of any one stack of the tray groups 2C, 2D and 2E in the unloader section is filled with ICs, a tray of this empty tray group 2B is conveyed onto the tray stack of the corresponding tray group and is utilized to store ICs therein.
In the aforementioned IC handler, the subject apparatus or structure to which the present invention is applied is an IC transporting apparatus comprising the contact arm 6 for carrying ICs from the turntable 4 to the testing section 7 and an IC transporting apparatus comprising the carrier arm 11 and the transfer arm 8 for conveying ICs from the testing section 7 to the carrier arm 11.
FIG. 3 shows a structure of a contact chuck portion for picking up ICs out of positioning recessed portions 5 formed on a prior art turntable 4. A reference numeral 12 denotes the entire structure of the contact chuck. The contact chuck 12 comprises a supporting plate 13, guide pins 14 implanted on this supporting plate 13, suction unit 15 for picking up ICs by suction, and a lead pusher (a tool for pressing or pushing lead terminals of an IC) 16 surrounding this suction unit 15.
The suction unit 15 comprises a sucker 15A mounted on the lower or forward end portion of the suction unit 15 and a sucking path 15B for aspirating air through the sucker 15A. The lead pusher 16 is arranged such that the suction unit 15 is positioned in the center of the lead pusher 16 and is surrounded by the lead pusher 16. This lead pusher 16 is adapted to perform operation of defining an IC to a predetermined position so that the suction unit 15 can pick up by suction an IC being accurately located on the predetermined position when the suction unit 15 picks up the IC.
That is, the forward or lower end portion of the lead pusher 16 has a tapered surface so that the lead pusher 16 can get into the positioning recessed portion 5, and the tapered end portion is inserted into the positioning recessed portion 5. By inserting the end portion of the lead pusher 16 into the positioning recessed portion 5, the sucker 15A can approach the IC and come in contact with the IC to pick up the IC by suction. At this time, the lead terminals of the IC are forced to engage with the inner sides of the end portion of the lead pusher 16, and hence the IC is located to a position determined by the lead pusher 16 and then the IC is picked up by suction.
Further, the lead pusher 16 performs operation of pushing the lead terminals of the IC against an IC socket in the state that the IC is conveyed to the testing section 7 and of maintaining the electrical contact between the IC and the IC socket. Therefore, at least a portion of the lead pusher 16 which contacts with the lead terminals is formed of an insulating material. In the illustrated example shown in the drawing, a case is shown where the entire lead pusher is integrally formed of an insulating material by molding.
The contact chuck 12 is supported by a member 17 hanging from the contact arm 6 (not shown in FIG. 3) and is movable in the up-and-down (vertical) direction and in the rotating direction of the contact arm. A shock absorber 18 lies between the member 17 and the contact chuck 12. This shock absorber 18 consists of a plate 18A mounted on the lower side of the member 17, rods 18B hanging from the plate 18A, a plate 18C hanging from the rods 18B and springs 18D each applying a predetermined pressure between the plates 18A and 18C.
Rods 13A stand upwardly on the supporting plate 13 which is a part of the contact chuck 12. The contact chuck 12 hangs from the member 17 through the shock absorber 18 by causing the rods 13A to pass through the plate 18C which is a part of the shock absorber 18 and to engage the rods 13A with the plate 18C.
When the contact chuck 12 moves downwardly and approaches the positioning recessed portion 5, it is necessary to align the central position or axis of the lead pusher 16 with the center or central axis of the positioning recessed portion 5. To this end, in the illustrated prior example, a pair of guide bushes 21 is provided on the turntable 4 for each of the positioning recessed portions 5, and also guide pins 14 which fit in the guide bushes 21 are provided on the supporting plate 13 in such a manner that the guide pins 14 project downwardly from the supporting plate 13 whereby the center of the lead pusher 16 can align with the center of the positioning recessed portion 5 by engaging guide pins 14 with the guide bushes 21.
For this positioning and aligning operation, a play or clearance is provided between each rod 13A and a through-hole through which each rod 13A passes and formed in the plate 18C which is a part of the shock absorber 18 so that the positioning of the contact chuck 12 to each recessed portion 5 is made possible within the range of the play between the rod 13A and the through-hole.
In the prior art apparatus, positioning and alignment of the contact chuck 12 to and with the positioning recessed portion 5 has been made possible by means of the guide bushes 21 and the guide pins 14. Since the two guide bushes 21 must be provided for each positioning recessed portion 5 formed on the surface of the turntable 4 as shown in FIG. 2, many guide bushes are required and hence the cost of such parts is high.
In addition, since a multiple of guide bushes 21 must be provided, even the heat capacity of only the guide bushes 21 becomes large, and thus a heating and heat absorbing or cooling apparatus of large capacity must be provided for heating and cooling the thermostatic chamber 9. Further, because of a large heat capacity required, there is a shortcoming that it takes a considerable time until the temperature within the thermostatic chamber 9 reaches a target temperature and stabilizes to that temperature.